Precisely how Tory will London's immediate future have become by this time next week? There now seems little doubt that its political hue will have moved across the spectrum, away from red and towards blue. But how far and to what effect? The crucial factor is, of course, the outcome of the general election. David Cameron seems to have won last night's TV debate, but we don't yet know how much difference that has made. The BBC's (pre-debate) poll-of-polls projects a hung parliament, with Labour narrowly winning the largest number of seats in spite of Gordon Brown's woes. Even if Cameron has a fraction more momentum now, the final result remains in doubt.

If the Tory leader does win Downing Street - which I suspect he will - there will be big implications for Londoners. After the borough elections - also to be held next Thursday, of course - it is likely that Labour will have overall control of only four of the capital's 32 council compared with a Tory haul of at least 14 and half a dozen under the full command of the Lib Dems. A Conservative government pledged to an early "emergency" budget and with "localist" plans whose full meaning remains obscure, is hungrily anticipated by boroughs of a rather Thatcherite character such as those sure to still be running Barnet, Westminster and Hammersmith and Fulham.

The impact will be all the greater if Cameron secures a Commons majority rather than having to form a minority government with all the compromises and constraints that entails. London Conservatives at different levels of government will find their power to do more of what they want less than they would wish if their leader fails to pass the Commons "winning post" of 326 seats. And the further short he falls, the less liberated they will be.

Many Londoners can do a lot to influence the outcome of the UK election. As I wrote earlier this week, the polls suggest that the Tories won't make gains among London's 73 constituencies on the scale they must have hoped for a few weeks ago. Unless the Clegg surge peters out or proves to have been made of orange blancmange, Lib Dem candidates in the suburban south-west can be confident of holding off Cameron's and be hopeful of overhauling the Tory in Ealing Central and Acton. Yet the outcome in around half a dozen Labour-Conservative marginals that look very finely poised could be absolutely crucial to the future of not just London but Britain too.

Boris, two years onMayor Johnson is about to celebrate two years of being Britain's most powerful Conservative. If he is soon to be deprived of that position we will be able to judge to what extent his City Hall administration so far has been a dry-run for a Cameron government. Should the comparison prove valid, any forthcoming Tory nightmare might not be as terrifying as some fear. Despite a few over-reported differences with his fellow old Etonian, Boris's path has been pretty faithful to the "caring Conservative" blueprint. His spending cuts have been less savage than they might have been and his Mayoral incarnation thankfully - and very wisely - less harrumphingly, right-wing than the Daily Telegraph one.

Time will tell, but a more interesting question is how Mayor Boris will get along with any new Conservative government compared with the Labour one he's been dealing with so far. A large part of the job of any London Mayor is the unseen business of lobbying Whitehall for money. Boris has been provided with large sums by Labour ministers for such as housing, policing and transport. Will George Osborne be as obliging when Boris holds out his cap? Might he privately agree with me - and with the private Boris too - that the financial cost to London of crowd-pleasing election promises about bendy buses, the "New Routemaster" and halving the size of the congestion charge zone have proved very costly financially?

Boris, I suspect, will be readying himself for battles with the Treasury more fierce than any he's had so far. And if his fellow Tories in Westminster disappoint him, be sure that he'll be urging Londoners that they, not he, should take the blame.

London blogosphereAll over the capital Top London Bloggers have been enhancing the quantity, quality and local flavour of election coverage. Brockley Central has run a week-long series of "virtual hustings" for parliamentary, mayoral and council candidates. Hackney's Blood and Property has been burrowing behind the edifices of Labour support in Hackney. West Hampstead Life, NW6 and the Worcester Park blog have carried interviews with candidates and voters. More, more!

Coming upIt's a bank holiday weekend and, not for the first time, I direct you to my friends at Londonist and Ian Visits who are much better than me at having fun. Did I mention that there are elections next Thursday? If not, I really, really should because they could mean that next week's Metropolitan Lines will be sent out later in the day than usual so that I'm able to report, half-sensibly (and half asleep) on the parliamentary outcomes in the capital. No doubt I'll be blogging and tweeting through the night as well. So keep in touch.